In recent years, a CCFL (Cold Cathode Fluorescent Lamp) has been used as a backlight of an LCD display for a computer or an LCD TV. A burst dimming control is used in order to control the brightness of the discharge lamp used for the above equipment, thereby alternately appearing a lighting time period for lighting the discharge lamp and a lights-off time period for turning off the discharge lamp.
In the burst dimming control, a lamp current flowing through the discharge lamp is required to be controlled to have a target brightness value over the entire lighting time period. However, it usually takes time to increase the lamp current up to the target value within a predetermined lighting time period. Overshoot of the lamp current sometimes occurs immediately after the start of the lighting time period. Thus, control for adjusting the lamp current to the target value within a short time is generally difficult.
An object of the present invention is to provide a discharge lamp lighting device capable of controlling a lamp current to a target value within a short time while preventing occurrence of overshoot when lighting the discharge lamp using burst dimming control.